Girls, Woman who works at my gym always looking?

Woman who some times chats with receptionist at my gym always looking as I walk in and trying not to smile after I first saw her and thought she was cute. After her work she goes to the gym and we always glancing then when I workout near her she stares at her phone etc , same old keeps happening stares when I walk in and smiles to herself then glances. When I was working out with my friend talking about how I build my arms etc she always listens in with her friend untill I said for weeks never spoken until I told my friend I wasn't coming for a while she asks if I'm using something then I ask if she's finished and she was really polite and then she walked out 20 mins later with her friend giving me a final look before she walks out the doors? What's this about